Balance

ABSTRACT

A self-adjusting balance comprising a stirrup supporting a rotatable disk at its center. The front face of the disk is graduated in degrees from 0* to 90*, the graduations continuing on the reverse face from 90* to 0*. At the rim of the disk there are two slots, at diametrically opposite 0* marks, to accommodate cords, one to be connected to a weight to be measured and the other to a standard weight, the weight to be measured being connected to the cord in the front face 0* slot with the cord lying circumferentially against a portion of the rim of the disk to the point where this cord hangs free and vertical, the standard weight being connected to the cord in the diametrically opposite slot, this cord hanging free and vertical.

United States Patent Leonard 5] July 25, 1972 [54] 737,859 10/1932France ..177/216 72 I I I 1 men or Leonard 184 Holden St H01 PrimaryExaminer-Robert S. Ward, Jr.

Attorney-Charles R. Fay [22] Filed: July 21, 1971 [21] Appl. No.:164,714

FOREIGN PATENTS OR APPLICATIONS 567,515 12/1923 France ..177/224 [5 7]ABSTRACT A self-adjusting balance comprising a stirrup supporting .arotatable disk at its center. The front face of the disk is graduated indegrees from 0 to 90, the graduations continuing on the reverse facefrom 90 to 0. At the rim of the disk there are two slots, atdiametrically opposite 0 marks, to accommodate cords, one to beconnected to a weight to be measured and the other to a standard weight,the weight to be measured being connected to the cord in the front face0 slot with the cord lying circumferentially against a portion of therim of the disk to the point where this cord hangs free and vertical,the standard weight being connected to the cord in the diametricallyopposite slot, this cord hanging free and vertical.

7 Claims, 3 Drawing Figures Patented July 25, 1972 0 K o uk um WAXEdward H. Leifii??? BALANCE The two inexpensive weighing devices incommon use are the spring-type scale and the beam balance. Thespring-type scale, although self-adjusting, is limited to a rangedetermined by the stifiness of the spring. In order then to measure awide range of weights one must either sacrifice sensitivity by using arelatively stiff spring or use several instruments with different springstiffnesses.

The common inexpensive beam balance is not self-adjusting, requiringinstead that the operator move a rider or riders in order to bring thebeam to its balanced position, an operation which, particularly for aninexperienced operator, may take considerable time.

With the beam balance and usually with the spring-type scale (exceptwhere provided with English-metric equivalent units) calibrations whichappear on these instruments allow one to weigh within only a singlesystem of units, i.e., grams or ounces or pounds, etc.

SUMMARY OF THE INVENTION The present invention is a device for weighingan object by balancing the torque produced by the object on a calibrateddisk with the torque produced by a standard weight acting so as toproduce counter-rotation on the same disk.

The magnitude of the weight to be measured is a function of the anglethrough which the disk rotates and the weight of the standard. Knowingthe weight of the standard, the unknown weight can be determined byreferring either to a sine table which may appear on the front face of astirrup supporting the disk or to a table of reciprocal sines, which mayappear on the reverse side of the support.

The proposed device consists of few and simple parts. It eliminates thelimited range restriction inherent with the spring-type scale, for withthe proposed device the value of any weight can be determined subjectonly to the physical strength of the instrument itself. The sensitivityof the measurement can be controlled by the choice of thecounterbalancing standard weight used.

The proposed device is self'adjusting in that the effective moment armis determined automatically as the disk rotates to assume a balancedposition thus eliminating the necessity for the operator manually toslide a rider on a beam.

The proposed device may be used within any system of units (grams,ounces, pounds, etc.,) determined not by the characteristics of thedevice itself but by the unit associated with the standard weightemployed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view in front elevationillustrating the balance, part being broken away;

FIG. 2 is a view illustrating the front face of the disk and thedetermination of the value of X where X S; and

FIG. 3 is a like view at the reverse face of the disk and determinationof the value of X where X S.

PREFERRED EMBODIMENT OF THE INVENTION The construction of the balance isshown in FIG. 1. A disk 10 having a center pin 12 is rotatably mountedthereon between the spaced legs 14 and 16 of a hanger l8.having asupporting ring 20 at the closed end thereof 22. This hanger may be openat the bottom or closed as shown in FIG. 1. A graduation 24 from to 90is placed as shown on one face of the disk and on the opposite face agraduation 26 continues from 90 to 0. Thus 180 of the disk bearsgraduations.

At each 0 mark partial slots 28, 30 extend radially from the edge of thedisk into through access holes 32, 34 respectively. A cord 36 with anend knot 38 is mounted in slot 28 and draped on the periphery of thedisk. A like cord 40 with knot 42 is mounted in slot 30, and standardweight S is secured thereto. The cord 36 is to support unknown weight X.The hanger may be clear, or a sight hole 44 can be used to read thegraduations at the top of the disk after rotation of the disk to balanceunder the influence of the weights.

Referring to FIG. 2, with the parts in balanced position, XR

SR- sin 9 or, X= 8- sin 9 where X weight of object (X S) S weight ofstandard R radius of disk 0 angle through which disk rotates If theweight of object X is less than the weight of the standard (as is thecase in FIG. 2) the rotation of the disk will be through an angle lessthan in which case the value of the weight of the object will be equalto the value of S times the sine of the angle through which the disk hasrotated. On the front face of the hanger may be printed a table ofangles and their sines in terms of which the weight of the object canreadily be determined.

If the weight of object X is greater than the weight of standard S (seeFIG. 3) the rotation of the disk will be through an angle greater than90. In this case the scale indicating angle of rotation appears on theopposite face of the disk. I-Iere (FIG. 3) SR=XR' sin 9 or, X= S 1 )(sin9) where X weight of object (X S) S weight of standard r= radius of disk9 (angle through which disk rotates) On the corresponding face of thehanger may be printed a table of angles and the reciprocals of theirsines in terms of which the value of X can readily be determined.

It will be noted that with the table of sines and the table ofreciprocal sines appearing on opposite faces of hanger corresponding tothe scales which appear on opposite faces of the disk, it would bedifficult for anyone to use the improper table in making a calculation.

I claim:

1. A balance comprising a vertical disk, means mounting the diskcentrally thereof for free rotation, graduations in degrees at one faceof the disk, a first cord attached to the disk at its periphery in apredetermined relation to the graduations, a second cord attached to thedisk at its periphery diametrically opposite the point of attachment ofthe first cord to the disk,

a known weight attached to one cord,

an unknown weight attached to the other cord,

one cord hang free and vertical and the other cord being draped on thedisk at the periphery thereof, wherein the locations of the graduationsto the points of attachment of the cords to the disk ensuring that somearea of the graduations will appear at the top of the disk, and the saidpoints of attachment will be spaced from the top of the disk.

2. The balance of claim 1 wherein said graduations appear partly on oneface of the disk and partly on the opposite face.

3. The balance of claim 2 wherein the graduations at one face of thedisk are from 0 to 90.

4. The balance of claim 3 wherein the graduations at the opposite faceof the disk are from 90 to 0.

5. The balance of claim 4 wherein the graduations are continuous for 180of the disk. I

6. The balance of claim 5 wherein the sequence of the graduations is 0to 90 to 0.

7. The balance of claim 6 including radial slots at the 0 marks, at 180apart, the cords lying partially in the slots which form means forattaching the cords to the disk.

1. A balance comprising a vertical disk, means mounting the diskcentrally thereof for free rotation, graduations in degrees at one faceof the disk, a first cord attached to the disk at its periphery in apredetermined relation to the graduations, a second cord attached to thedisk at its periphery diametrically opposite the point of attachment ofthe first cord to the disk, a known weight attached to one cord, anunknown weight attached to the other cord, one cord hang free andvertical and the other cord being draped on the disk at the peripherythereof, wherein the locations of the graduations to the points ofattachment of the cords to the disk ensuring that some area of thegraduations will appear at the top of the disk, and the said points ofattachment will be spaced from the top of the disk.
 2. The balance ofclaim 1 wherein said graduaTions appear partly on one face of the diskand partly on the opposite face.
 3. The balance of claim 2 wherein thegraduations at one face of the disk are from 0* to 90* .
 4. The balanceof claim 3 wherein the graduations at the opposite face of the disk arefrom 90* to 0* .
 5. The balance of claim 4 wherein the graduations arecontinuous for 180* of the disk.
 6. The balance of claim 5 wherein thesequence of the graduations is 0* to 90* to 0* .
 7. The balance of claim6 including radial slots at the 0* marks, at 180* apart, the cords lyingpartially in the slots which form means for attaching the cords to thedisk.